/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package com.antgroup.geaflow.state.iterator;

import com.antgroup.geaflow.common.iterator.CloseableIterator;
import java.util.Iterator;
import java.util.function.Function;

/**
 * This class accepts a iterator and makes its value transformed.
 */
public class IteratorWithFn<T, R> extends BaseCloseableIterator<T, R> {

    protected final Function<T, R> fn;

    public IteratorWithFn(CloseableIterator<T> iterator, Function<T, R> function) {
        super(iterator);
        this.fn = function;
    }

    public IteratorWithFn(Iterator<T> iterator, Function<T, R> function) {
        super(iterator);
        this.fn = function;
    }

    @Override
    public boolean hasNext() {
        return iterator != null && iterator.hasNext();
    }

    @Override
    public R next() {
        return fn.apply(iterator.next());
    }
}
